Generally described, computing devices and communication networks can be utilized to exchange information. In a common application, a computing device can request content from another computing device via the communication network. For example, a user at a personal computing device can utilize a software browser application to request a Web page or application from a server computing device via the Internet. In such embodiments, the user computing device can be referred to as a client computing device (“client”) and the server computing device can be referred to as a content provider.
Content providers are generally motivated to provide requested content to client computing devices often with consideration of efficiency, reliability, and/or cost associated with the transmission of the content. For larger scale implementations, a content provider may receive content requests from a high volume of client computing devices which can place a strain on the content provider's computing resources. Additionally, the content requested by the client computing devices may have a number of components, which can further place additional strain on the content provider's computing resources.
Some content providers attempt to facilitate the delivery of requested content, such as Web pages or resources identified in Web pages, through the utilization of a content delivery network (“CDN”) service provider. A CDN service provider typically maintains a number of computing devices, generally referred to as “points of presence” or “POPs” in a communication network. The service provider or POPs can include one or more domain name service (“DNS”) computing devices that can process DNS queries from client computing devices. Additionally, the POPs can include network resource storage component that maintain content from various content providers. In turn, content providers can instruct, or otherwise suggest to, client computing devices to request some, or all, of a content provider's content from the CDN service provider's computing devices. As with content providers, CDN service providers are also generally motivated to provide requested content to client computing devices often with consideration of efficiency, reliability, and/or cost associated with the transmission of the content.